The documents overstated the cash in Dewhurst's state campaign account by hundreds of thousands of dollars, thereby allowing Barfield to conceal money he allegedly had taken from the campaign committee. His alleged improprieties go back to 2008.

Prosecutors confirmed Friday they have opened an investigation into the allegations against Barfield, although he has not been charged.

The allegations came a month after Barfield, who invests in real estate, failed to pay the latest of several defaulted settlements with S&K Development Co., an attorney for the developer told the Associated Press on Friday. A state district judge in 2009 awarded the corporation a $2.2 million judgment against Barfield and his defunct companies for failing to repay the loan.

Curtis Kurhajec, an attorney for the developer, told the AP that S&K Development originally lent Barfield and his companies about $1.7 million for a development project in Colorado that never broke ground. Kurhajec said Barfield again defaulted on the latest settlement, due on Nov. 1, of $506,000.

Barfield, who also managed Dewhurst's 2010 re-election campaign, could not be reached for comment. His attorney, Brian P. Casey, declined to comment.

After contacting the Travis County District Attorney's office on Dec. 20, the Dewhurst campaign committee filed 11 amended finance reports with the ethics commission.

"It was recently discovered, unknown to the officeholder and the treasurer of the committee, that the contribution balance shown on the original report was false," the corrected report said, naming Barfield as the campaign official responsible.

Dewhurst 'shocked'

In the original document filed in July, Dewhurst's state campaign listed cash on hand of $777,245. In the corrected report, filed last week, that amount had been changed to $7,226. Each amended report contains identical language.

Holly Taylor, an assistant Travis County district attorney in the public integrity unit, confirmed that the unit had received a referral from the Dewhurst campaign committee and had opened an investigation.

The unit investigates felony cases involving public officials.

"The lieutenant governor is shocked and dismayed that a former senior trusted adviser would steal from the campaign account for his own personal gain," said Rob Johnson, a spokesman for Dewhurst.

"The level of betrayal is stunning. The proper authorities have been contacted, and we will work with them and trust that the matter will be handled appropriately," Johnson said.

Barfield has profited greatly from his long association with Dewhurst, beginning with the lieutenant governor's first run for political office in 1998. During the 2007 legislative session, for example, the Dewhurst campaign paid him $379,167 in political consulting fees.

Barfield also has had a long political association with Charles and David Koch, the Wichita, Kan., billionaire brothers who contribute millions to conservative candidates and causes.

In 1998, the Wall Street Journal reported that Barfield was a Koch brothers' consultant on a plan to give $1.8 million to a Republican organization that allowed party candidates to bypass campaign-finance limits on political ads during the 1996 campaign cycle.

Worked in many races

Based in Austin, Barfield also has worked for a number of Republican candidates over the past 25 years, including 1990 gubernatorial candidate Clayton Williams, a West Texas oilman and rancher who lost to Democrat Ann Richards.

Austin political consultant Bill Miller said he had known Barfield for a long time, describing him as "courtly, sort of a Southern gentleman."

"I was shocked when I picked up the paper and saw that story today," Miller said. "I just couldn't believe it."

Emphasizing that he is unfamiliar with the details of the allegations against Barfield, Zeidman suggested that it's easy to embezzle money from political campaigns.

"Given how fluid campaigns are, with money coming in on a daily basis and going out on the same basis, it wouldn't surprise me at all," Zeidman said. "In a campaign you don't set up a major infrastructure, because you can't afford the money and you can't afford the time."

Miller agreed.

"If you control the books, you can do whatever you want," he said. "There's a lot of money, a lot of pressure and very little controls."